My 03 SY-250 would not run today so I took it apart and the inside of carb and intake was coated with a white powdery residue. I have never seen this before. I was able to wipe the residue off with a cloth. It didn't disolve with carb cleaner. I switched to Motul 800 full synthetic a while ago. I used to use Motul 600 full synthetic and never had this problem. Has any one noticed this problem with Motul 800? I also switched from leaded race gas to unleaded about the same time.

Any help would b appreciated.

Thanks,

DFW

Hi there, you should be runnung the bike on semi synthetic. this will stop the exhaust clogging up ect. it was told this by nigel birkett. not sure if this is why you are haveing problems as i used fully synth motul on other bikes with no problem.

White powdery residue ey? Not being doing any border crossing recently have you?

Sounds the like stuff I find on inside of my bikes carbs when they've been stood for a while.

I used to solve it by turning off the fuel and running till the carb was dry before I left them but this was on 4 strokes and I'm not sure how sensible this would be to do on a 2 stroke due to lubrication.

I'm also using unleaded if this has any bearing on anything.

Edited May 12, 200818 yr by tt5th

Hi DFW,

Usually caused by moisture in the carb, water getting in and not being cleaned out. Completely strip out the carb, totally, scrape off residue where you can and blow out the passageways.

Bye, PeterB.

If it's pump gas it could be due to moisture absorbed by the ethanol.